News Round-Up

The Society celebrated the 50th anniversary of the first run by Edsac with a
seminar at the Science Museum on 10 May. Society Chairman Brian Oakley
introduced the event as "a celebration of 50 years since Edsac worked and
also more importantly a celebration of what the Cambridge Computer Laboratory
has done over the past 50 years". A report of this event can be found
starting on page 7.

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The seminar was followed by a reception in the library of the Director's
Suite. Brian Oakley took advantage of the occasion to pay tribute to the
Society's sponsors. For the SSEM project Oakley acknowledged the University
of Manchester, the Manchester Museum of Science and Industry, and "above all
ICL for not just the filthy lucre but also the people". For the Bombe
project he thanked AutoCad, Nortel, Quantel and the Nortel retired group. For
general support of the Society's activities, Oakley acknowledged the BCS and
our two corporate sponsors, Vaughan Systems and ICL.

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Ewart Willey retired from the Committee at the AGM on 10 May. Ewart was the
first Chairman of the Society's Committee, a role he filled till 1992. Since
then Ewart, a former President of the BCS, has continued to give us the
benefit of his wise counsel as a "backbench" member of the Committee. We
wish him well for the future.

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All other officers and members of the Committee were re-elected by the AGM.

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Len Hewitt has been formally appointed Chairman of the Pegasus Working Party,
in succession to Chris Burton. Len has been guiding the activities of the
working party since Chris started work on the Small-Scale Experimental
Machine project in Manchester.

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We are delighted to report that the Committee's Science Museum
representative, Doron Swade, has been promoted to the post of Assistant
Director and Head of Collections.

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We are grateful to Roger Middleton for the donation of two sets of magazines
to the Society: one of Personal Computer World running from 1978 to
1998, and the other of Byte from 1981 to 1998. All are in original
condition: where there was a floppy disc or CD-ROM supplied with an issue
this is still attached. The collection was started by Dr Middleton's father
Ron, who used to work for ICL, and continued by Dr Middleton himself, who is
Reader in the History of Political Economy at the University of Bristol.

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The Science Museum is planning to incorporate the Pilot Ace in the new
Museum of the Modern World gallery, due to be opened next year.

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The Station X series on Channel 4 television has led to an immense
increase in the number of visitors to the Bletchley Park open days. As a
result, consideration is being given towards opening the Park every weekend,
instead of alternate weekends as at present.

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The Leo Computers Society has now set up a Web site. The address is
<www.man.ac.uk/science_engineering/CHSTM/leo>.

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The Leo Computers Society is organising a reunion for anyone who worked for
Leo Computers, its successor companies, or users of Leo systems. It will
commemorate the 50th anniversary of the start of work on Leo I. The reunion
will take place in London on Friday 15 October 1999. Anyone interested should
contact the Web site given in the previous paragraph for further information,
or alternatively should ring organiser Peter Byford on 01920 463804.

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We have received information about an Australian organisation called Back
(Burnet Antique Computer Knowhow) which, to quote its own literature,
"specialises in the provision of creative, interesting and memorable
displays of computing icons in foyers and entrances". To provide this
service, Back has a collection of computing and data processing artefacts
dating back to 1910, stored in over 60 six foot cabinets, as well as over
6000 literature items. Readers wanting to know more can contact Back Pty Ltd
at PO Box 847, Pennant Hills, NSW 2120, Australia, or e-mail proprietor Max
Burnet at <mburnet@nsw.bigpond.net.au>.

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Does anyone know of any survivors, intact or partial, of any of the following
early machines: BTM 541, 542, 550 and 555 calculators; BTM 1201 family;
Powers Samas EMP and PCC; or ICT 558? The Secretary would be grateful if
anyone who does would contact him with the details.

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Jack Howlett, a mathematician who played a major role in pioneering the use
of computers for complex scientific applications, has died aged 86. Jack, who
was best known as the Director of the Atlas Computer Laboratory at Harwell
from 1961 to 1975, was also for many years a distinguished editor of the
ICL Technical Journal. Jack was an enthusiastic member of the Society and
was often seen at our meetings.

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Membership of the Society currently stands at around 670.

A History of Manchester Computers

As part of the 50th anniversary of computing celebrations in Manchester last
year, Simon Lavington and the British Computer Society have produced a book
describing the history of Manchester University's five prototype computers
built over the period 1946 to 1975.
Anybody who missed the celebrations or would like to know more about
Manchester's innovations is recommended to obtain a copy of this book. Its 56
pages provide a detailed description of the five prototype computers, place
them in the context of contemporary computer developments elsewhere, and are
copiously illustrated with photographs, charts and program listings.
"A History of Manchester Computers" by Simon Lavington is published by the
British Computer Society at 1 Sanford Street, Swindon, Wiltshire SN1 1HJ, and
has ISBN number 0-902505-01-8. The price is £6.00 to BCS and CCS
members, £8.00 to non-members. Contact Ian Jones, BCS Publications
Manager, on 01793 417417 for further details.

Cambridge's Golden Jubilee

Nicholas Enticknap

An important UK computing golden jubilee took place on 6 May 1999.
Fifty years earlier to the day, Cambridge University's Edsac ran its
first program, the production of a table of squares. In 2 minutes 35
seconds history was made.

The Society helped to celebrate the anniversary with an afternoon
seminar at the Science Museum on 10 May. A month earlier the
university ran its own commemorative event, Edsac 99, and the
Society's event was based upon this.

The Cambridge story has a very different starting point from the
contemporary developments at the other pioneering university,
Manchester. Whereas the Small-Scale Experimental Machine project grew
out of electrical engineering research, Edsac was the fruit of
research into computational methods. Manchester needed to test a
cathode ray tube memory, Cambridge was looking to build on
computational advances made with differential analysers.

These differing backgrounds had an important influence on both the
approach to and the progress of these two influential early UK
computers.

Maurice Wilkes told the Science Museum audience that the starting
point for Edsac was when "I was invited to the Moore School for a
series of lectures on electronic computers". The potential of the
Eniac/Edvac project he learnt about had an immediate impact on Wilkes,
and "I began to sketch the design of Edsac on the Queen Mary on the
way home".

Wilkes summarised the design principles he arrived at thus: "It was
to be simple; adaptable to user needs; a serial machine, modelled on
Edvac; to have a double length accumulator; and to be a fixed point
machine, with a 34-bit word plus sign".

A major practical problem was the choice of memory. For Manchester
University, proving radical new memory technology was the major point
of the exercise; for Cambridge, producing a working computational
device was the objective, and that meant using tried and tested
components. But what?

Wilkes chose mercury delay lines: this decision, he revealed, "was a
suggestion of Eckert's", but he added that "this was the only sort
of memory that offered itself".

Wilkes himself was "what would now be called Chief Architect". Much
of the detailed design work was done by people he recruited.

"PJ Farmer joined in 1946, and established a mechanical workshop. He
became Principal of Systems. I was fortunate to meet Tommy Gold, who
had worked on radar in the Admiralty. We had got pulses circulating by
mid-January 1947. Tommy Gold introduced me to Renwick, who joined us
in March 1947."

Wilkes continued, "Renwick built up the machine and made it work as a
whole. As time went on, I did less design and testing, and the whole
responsibility fell on Renwick. Then on 6 May 1949, the machine
suddenly did a calculation, of a table of squares."

From this point the emphasis switched from basic development to the
provision of a service. "Edsac affected a very large number of users.
There was always the idea that it should be a workhorse, and not just
used for one or two big problems. So we made it available to
laboratory research students from all departments at the university.
They had to do their own programming. There was no positive selling:
we let them find out about the computer for themselves, usually from
their juniors."

David Hartley, who made a presentation covering the service provided
by the Cambridge Laboratory over the entire half century since 1949,
pointed out what a difference Edsac made. "It was 1500 times faster
than the previous manual computational methods", which as he said was
the biggest improvement ever made. Its actual speed was 300
instructions per second, and the user base numbered about 50.

Still, it soon became obvious that Edsac was only the start, and that
a new machine incorporating the latest technology plus some new ideas
that arose out of experience would offer substantially greater
performance. Design work on Edsac 2 started in earnest as early as
1953.

The major significance of this machine, said Wilkes, was that "It
showed that microprogramming was a viable system on which to base a
major machine, despite the use of vacuum tubes. It was not easy to
make a read-only memory out of vacuum tubes."

Indeed, "The Edsac 2 control matrix in which the microprogramming was
stored was based on 8mm cores, which were very hot. Had transistors
not come along I think microprogramming might have been stillborn.
Everything was controlled from the microprogram, even the sequencing
of operations in the core memory."

Another less well-known claim to fame for this second Cambridge
machine was that "We were also a pioneer of bit-slicing. The word
length was 40 bits, and we built 40 chassis, each containing one
flip-flop and one stage of the adder. It made maintenance very easy.
That idea was re-invented for the 2900 series MSI chips."

Memory was once again a major problem during the design stage. "There
was an advanced Williams tube by then, but I was reluctant to get
involved... Fortunately magnetic cores came along. We had contemplated
a mercury memory with 40 tanks."

Wilkes continued, "Edsac 2 had a memory of 1000 40-bit words, twice
the capacity of Edsac 1. As time went on, it seemed woefully
insufficient. There were just not enough bits in an address to address
more than 1000 words. So I dreamed up a system of indirect addressing,
and Wheeler perfected and implemented it.

"In one of the first bits of computer industry PR, we called it 'main
memory'. The old memory, which we called 'high-speed memory', was used
for programs; in the main memory you could put numbers and program
stacks. Most main memory accesses took two memory cycles. That gave an
access time of six microseconds, twice that of the high speed memory.
We bought it from Ampex. Capacity was 16K words."

Usage of computing facilities became more widespread during Edsac 2's
time: David Hartley observed that it supported 200 users. The
machine's speed he gave as 10,000 instructions per second, 40 times
the speed of the earlier machine. Edsac 2 ran its last program in 1965
at what Hartley described as "the first official closing down
ceremony, at which it played 'The Last Post'."

The story from there was taken up by Roger Needham, not in person as
he was away in the United States on business, but via a video
recording of his presentation at the Edsac 99 event.

By the early sixties Atlas, developed at Manchester and sold
commercially by Ferranti, was setting the computing standards.
"Everybody in the scientific community wanted an Atlas, but we
couldn't afford one. A decision was taken with Ferranti to collaborate
on producing a cost-reduced version of Atlas. This involved doing away
with the paging system, and developing a different peripheral and
memory organisation.

"Without the paging system we couldn't use the Atlas operating
system, so jointly with Ferranti and its successor ICT we set off to
design a new operating system from scratch." The resulting system,
known as Titan "was thrown open to all comers" in March 1967.

During the design stage the decision was taken to make Titan a
timesharing system. According to Needham, "Maurice Wilkes went to the
US and saw MIT's CCSS system, the first timesharing system, with
Flexowriters as terminals. He came back with the strong conviction
that this is what must be done at Cambridge."

According to David Hartley, "It had a pragmatic approach to resource
sharing. It had non-interactive timesharing ('normal mode') as well as
interactive timesharing ('expensive mode')."

Titan pioneered a number of new concepts. Roger Needham told the
audience, "Our system was innovative in that it had a feature that
restricted the use of a program as well as user access. This was not
in Multics or Unix. That avoided a number of programs having system
privileges when they didn't really need it.

"Within its limitations, that system ran the computer with amazing
efficiency. None of us had any experience of multi-access systems. We
originated the password file protection mechanism."

Cambridge decided to grasp the bull by the horns, and make the system
available on a 24x7 basis on the outset. "That was no problem", said
Needham nonchalantly, "and we never looked back".

Another pioneering aspect of Titan was the development of the BCPL
programming language: Needham observed that "all the Xerox Parc
software was written in BCPL initially". Robin Shirley pointed out
from the audience that BCPL has an even greater claim to fame as the
direct ancestor of C and C++.

David Hartley claimed that "Titan set many standards: some aspects
laid the groundwork for the success of Unix." During its time the
user base rose to 900: performance was now up to a quarter of a
mips - 25 times as powerful as Edsac 2.

During Titan's lifetime, there were changes in the world outside
Cambridge which had a large influence in the choice of the next
machine. According to Roger Needham, "The IBM 360 became the {\em de
facto} standard for scientific computing. That made it easy to swap
data and programs. So you needed a 360/65."

In fact it was IBM's successor machine, the 370/165, which replaced
Titan. It was installed at the end of 1971, and became operational in
March 1972.

This first 'off-the-shelf' mainframe at the university was not
entirely to the liking of a department used to designing systems with
their own users' requirements in mind.

According to David Hartley, the 370/165 "was a most user-unfriendly
system. TSO was incompatible with the batch job system; job entry was
by punched cards.

"So we produced Phoenix, a user-oriented front-end language. That
lasted through to the demise of the last mainframe in 1995."

This period, from the installation of the 370/165 to the arrival of
the personal computer, was described by Hartley as "the Golden Age of the
Computing Service". During it, the pioneering emphasis changed away
from computer technology towards networking, as described to the
Science Museum audience by Andy Hopper. Work on the Cambridge Ring
started as early as 1974, before even embryonic PCs were available.

The Cambridge Ring "had repeaters, access boxes for device
attachment, a 48 volt power supply converted to DC by repeaters, and
10 megabits per second speed. The maximum distance between the
repeaters, which contained core memory, was 100 metres.

"That evolved into The Cambridge Distributed System. From the later
seventies we had fibre links, the first and longest lived in the UK."

The arrival of the personal computer created problems for the
Computing Service, as it did in installations everywhere. "We did not
understand that microcomputers were real computers", admitted Hartley,
bravely labelling his description of this 1982-87 period "Getting It
Wrong".

"Getting It Right" is what has been happening since then. The major
new development during this period was that "We explored the
prospects of a city-wide network, and by 1992 that was in place. Most
student rooms are wired up to Ethernet."

This is a succinct description of a quite radical departure. Cambridge
University is scattered all over the city, and implementing a
campus-wide network was a major logistical exercise involving the
obtaining of wayleaves and the like as well as a massive financial
investment.

The installation of the network was accompanied by the adoption of two
new principles of operation by the Computing Service. First, that the
job of the Service was to "operate a network and have full control
over it", and second that the Service "should not own
computers - users should do that".

So 50 years on we have the surprising situation that the University
which pioneered the provision of a computing service has no computers
of its own at all.

Donations

At the Society's Annual General Meeting in May, it was agreed that the
Society should try for another year to subsist without imposing personal
subscriptions, although further efforts would be made to attract additional
corporate subscriptions. Since the Society's running costs are partly covered
by a grant from the British Computer Society, it can be argued that those CCS
members who are also members of the BCS are in effect already paying for a
share of the work of the Computer Conservation Society through their annual
subscriptions to the parent organisation.
Those who are not members of the BCS are therefore invited to consider making
voluntary donations to help cover the costs. (These consist chiefly of the
costs of publication and postage.) Cheques should be made payable to The
Computer Conservation Society, and should be sent to:

BTM's First Steps Into Computing

Raymond 'Dickie' Bird

British Tabulating Machine Company (BTM) was one of the two dominant
players in the UK punched card industry before the arrival of the
computer. This article tells how the company entered the computer
industry itself, and gives the designer's view of the development of
the range of HEC (Hollerith Electronic Computer) machines.

BTM first became concerned about the threat to its business from the
emerging computer when IBM developed a product called the CPC (Card
Programmed Calculator). It sold well: they'd delivered 60 of them by
1951. But BTM had time to react because the CPC could not handle
sterling arithmetic. I often wonder how the British computer industry
would have developed if Britain had not had \pounds sd currency:
perhaps the 1900/2900 would never have got off the ground, and we
would have been buying all our computers from the Americans much
earlier.

BTM's first step was to recruit a man called Womersley from the
National Physical Laboratory (NPL). He was an entrepreneur with great
powers of encouragement and motivation, who had organised NPL's first
computer development, the Pilot ACE.

Womersley showed great commonsense in realising that other computers
under development in universities all over the world for scientific
purposes would be too big and too expensive for commercial use. The
technology was inappropriate, too: they had cathode ray tubes and
mercury delay lines, and anybody who had seen a mercury delay line
knew that it was not the sort of thing to put in a customer's office.

For design expertise, Womersley turned to Andrew Booth, lecturer at
Birkbeck College, London, who had designed a very small machine called
APE(X)C, which had been influenced by what he had seen during a two
year stint in the US. Doc Booth was a mathematician by training, but
he turned himself into one of the best engineers I have ever known. If
somebody else could do something for twopence, he could do it for a
penny. Just the person we needed to develop good small reliable
machines.

So Bill Davis, Dickie Cox and I were sent off to a rotting barn in a
village called Fenny Compton where Doc Booth was developing the
prototype of his APE(X)C machine.

Not only was the barn rotting, it was as cold as the Arctic. Doc
Booth's father was extremely parsimonious and objected to us using an
electric fire, so in the night he used to cut one of the bars. The
first job each morning was to wire it in again.

Eventually we finished copying the plans of the machine, returned to
base at Icknield Way, Letchworth and built an example of it, which we called
HEC 1. It was wired up solid: Booth didn't believe in plugs and sockets. How
right he was!

The machine was built with simple circuits, ex-Government valves
called 6J6s which were B7G-based double triodes. You could buy them in
cases of 100 from Gower Street: they were built by the million, which
made them reliable.

That's a point that many of the people who built early computers never
grasped - that reliability came with manufacturing in quantity.
The early computer engineers invented all sorts of ingenious
devices - circuits which counted up to 10, that sort of
thing - but they never worked well because nobody was making them
in volume. But that's a personal hobby horse.

I was assigned to Billy Woods-Hill's lab, which was not very large,
about 20' long. There was a bench along it, and he got a bit of chalk
and marked off 8' of it for me, which I thought at the time was pretty
mean. But when you consider he had four other people in there to
develop multipliers, which became the BTM Calculators - the 541,
542, 550 and 555 - it wasn't really so ungenerous.

Woods-Hill's group comprised Lorin Knight, Alec Trussell, Dickie Cox
and Martin Circuit. They were a good group, and we got on very well
with them. Billy Woods-Hill and I had both been RAF officers, and so
we thought alike, along the lines of 'When can we get down to the
pub?'.

It was a good time. We were the only people who thought we knew what
computing was about, and the rest certainly didn't have any idea. BTM
desperately wanted the machine, and so placed unlimited faith in us:
our brief was simply to get on with it. If I wanted something, there
was never any quibbling: the money was always found. I must hand it to
Cyril Holland-Martin, in particular, for ensuring that funding was
always there.

Later we moved to Number Three factory, still in Letchworth, where the
development people worked under Holland-Martin and Doc Keen, a brilliant
electro-mechanical engineer who was largely responsible for the
successful design of the Turing Bombe machines used to such good
effect at Bletchley Park during the war. Keen was hostile: he spread
rumours that if a lorry went by all the valves would fall out. He was
nearly right, but not quite! His attitude to his staff was "Don't you
go and look at those electronics folks, they're poison, you'll get
some infection". They used to creep surreptitiously into the lab to
find out what we were up to: we'd tell them and they'd sidle out
again.

After we developed the prototype HEC 1, the next step was to link it
to a tabulator. Now tabulators are synchronous devices, so if you
stopped one you could only restart it at the first point in a
revolution or cycle. This is no good for a computer, because
calculations take a variable time; it reads in a card, then calculates away,
then requires another card, then calculates for a different length of time,
and so on.

BTM had produced a tabulator called the E6/6, which had a multi-point
clutch. This consisted of a toothed gear wheel and an iron bar that
dropped into it and clutched, so starting a cycle. We adapted this tabulator
for the HEC 1. The men who did that were Steve Hare and another chap, Cyril
Mead, who was extremely good at converting things and joining them onto
things.

Mead was a super chap to deal with. You went to him and said, "I want
a row of relays there, to read all those cards, and I want it to drop
off at this and to pick up at that, and by the way I want to sense
that hole", and he did all of those things efficiently and without
fuss.

The HEC 1 had a very small drum - 16 tracks of 16 words, so a 256
word capacity. The drum was about an inch wide and five and a half
inches in diameter, and ran at about 3000 rpm. This was another
brilliant piece of work by Booth.

It was the things Booth didn't do that were also so very good. He
timed everything from the drum, so if the drum ran fast or slow the
machine kept pace with it. You didn't have a separate oscillator as
many computers did, which needed buffers to keep everything synchronised.

The drum had a clock track, and relays to control head access to the
tracks. There was a counter for registering the location of a record
as indicated by the clock track, followed by another for recording the
word address within the track. So when you wanted to retrieve data
from the drum, you entered the word address, set the head relays
moving, and when the clock track counter registered the same number as
the address, you'd found your record.

Data could be written to the drum either from the arithmetic unit or
from the control register, which was where you stored the instruction.
An instruction consisted of track and word for the operand; a counter
called C6 for shifting, multiplier timing or anything else you wished
to count; the location of the next instruction; and the
function - add, subtract, multiply, divide, shift, print, write,
or test.

The 'test' function was what made the computer what it was.
Calculators could test, and even tabulators could test up to a point,
but nothing like so thoroughly as computers. Effectively, any sort of
decision could be made by performing a series of tests.

The HEC 1 had two registers - an accumulator and a multiplier
register. They were cunningly arranged to allow you to perform a
double length multiplication. As you repeatedly added the multiplicand
to the product, it got longer while the multiplier got shorter, until
at the end of the calculation it had diminished to zero. This allowed
the product to fill the accumulator and then continue into the
multiplier register.

Then we were joined by an actuary! Ronnie Michaelson was taken on by
BTM because the Planning Division as it then existed under Kenneth
Elbourne wouldn't have anything to do with computers. Ronnie was a
highly intelligent man, and he became effectively the planning and
programming man.

He absorbed what I was doing like a sponge, and he used to make
valuable suggestions about how the commercial world would react. For
example, that we had to be able to read sterling - £sd. Our
initial reaction was 'we can't do this, it will foul up the machine',
but we quickly realised we had to work out how to do it.

It soon became obvious that everybody in the universities and other
computer development labs were thinking about what the {\em computer}
could do: how quickly it could calculate, how much storage it had and
so on. But what really mattered in the commercial world was getting
the information in and out. That had to dominate what went on inside.

So the questions that really mattered were: How fast can you read the
cards? How many columns do you want to read? What code is it going to be in?
How many print wheels do you want to use? Is it sterling or decimal?

The internals of the computer naturally mattered, but they had to be
tailored to these requirements. Most of our development work was aimed
not at making the computer a better calculator, but at making it
better at getting data in and out. The preoccupation with that (and
with cost and reliability) was the difference between the commercial
world and the university chaps.

The chronology of all this is that I joined BTM on 1 January 1951,
shivered in Booth's barn copying his plans during March of that year,
and had built the prototype and got it to work by the end of 1951.

At this point the company decided that we had to exhibit our machine,
to demonstrate to customers that we actually had a computer. So I was
told to build one fit for display. The prototype was just wires going
everywhere and held together by anything that came to hand. It worked,
but it wasn't fit to be seen in public!

So we made an exhibition version, which became known as HEC 2. It
essentially comprised four Post Office racks. They were a standard
size, bolted together from shelves and girders with holes all the way
down. They had covered power supplies at one end - if you put your foot
on the cover the power supplies shorted and there was a bright flash! We did
exactly that in the middle of the Business Efficiency Exhibition!

That was at Olympia, in 1953. When we got the machine there, of course
it didn't run. We had to get it working, but Olympia then was riddled
with electricians, all unionised up to the eyeballs. You couldn't do
anything - you couldn't switch the machine on, you couldn't even
put lights on or off!

So it took us all night to get the machine to work. That produced a
dirty great row with the electricians, who got double overtime for
staying all night - our Publicity Manager, Arthur Colton, was only
able to persuade them to stay on at an exorbitant price.

During this night session, the huge Olympia dome was as black as pitch
apart from the lights on our stand and one other pool of light a long
way off. So I walked towards the source of the light, and who should
it be but Powers Samas! They were trying to get the EMP (Electronic
Multiplying Punch) going.

At the exhibition we demonstrated some simple commercial programs, and
also noughts and crosses and bridge. The noughts and crosses display,
which Cyril Mead designed, worked absolutely beautifully\,---\,until
some schoolchildren came along and pressed all the buttons at once!

Ronnie Michaelson programmed the machine to bid a hand of bridge using
the Acol bidding convention. You chose your hand, fed it into the
machine, and out came the bid.

Then our Publicity man arrived, saying "I've got a calculating genius here
who thinks he can calculate quicker than the computer can". We said
"Nonsense", but we should have known better. This chap could multiply eight
decimal digits by eight decimal digits in his head.

We decided to set up a scheme to test him. We positioned the chap next
to a girl with a hand punch card machine, and somebody read out the
numbers, and while the girl was still punching the genius said, "The
answer is...". One should really not be too proud, there will always
be bloody something, as Peter Ellis used to say. He had a paperweight
with that aphorism engraved on the bottom of it.

On HEC 2 drum memory capacity had gone up to 512 words (or 32 tracks).
Many prospects felt that this was not enough for commercial computing
work, and it wasn't: it just couldn't handle the input and output. So
we decided to modify it for the scientific computing market.

The result was the HEC 2M. It used the chassis designed for the 541
calculator, a design that was riddled with plugs and sockets. Wires
connected the bases to the components, linked the components
themselves, and then connected the components to the plugs and
sockets. So there were three times as many soldered joints as on the
HEC 1.

Booth took one look at it and forecast that it would be "bloody
unreliable". He was absolutely right, but we had no option. The HEC
2M looked much more like a traditional BTM Hollerith machine.

We delivered about seven or eight HEC 2M systems. Customers included
GE Research Laboratories (Graham Morris sold that one), Thorn, Esso,
Boscombe Down, ARA and RAE, Bedford (they had two for wind tunnel
applications) and the Indian Mathematical Institute. We believe that
one was whisked off to the Soviet Union - we certainly never saw
it again.

I remember being summoned to Esso's site at Fawley because theirs
wouldn't work. It had an intermittent fault which I couldn't
understand - it didn't read the first card in properly, though
after that it worked perfectly. It took a field engineer of the old
school to sort that one out. He went straight to the relay sensor, took out
the armature, looked underneath it and found a little spot of grease. This
was preventing the armature from actuating properly the first time it tried
to move, though once it got going it was all right. There we had been,
sweating away for hours, and he just came along with a piece of cloth and
fixed the problem straightaway!

Generally the HEC 2Ms gave satisfactory service - luckily they
were all in environments that would accept the problems of early
computers.

We had a very good patent manager called Aldred Bowyer who was very
supportive. He came round regularly asking for patents: over my time
at BTM I provided him with 27, which sounds very impressive. Looking
back, I can see that most of them were trivial, but at the time I was
thrilled by the glory of all this innovation.

One day I asked Aldred, "We've patented all these things, but we
haven't had any royalties from anybody. Why not?". His response was,
"It's not like that, lad. There's IBM over there, patenting like
fury, and there's me over here, patenting like fury, and I meet with
their patent manager, and we stack patents up in front of each other,
measure how high they are, and if they're roughly equal, we
cross-license". So the requirement was to get as many patents as
possible. Aldred's response deflated me somewhat, which wasn't a bad
thing for a cocky young bloke.

Our next development was a machine for commercial applications,
essentially a HEC 2 with a number of enhancements specifically
designed for a commercial workload. This became known initially as the
HEC 4, and later as the 1201.

It had four registers instead of two. This allowed you to convert from
either decimal or sterling to binary as the data was input from cards,
a process impossible with just two registers. It had both a multiplier
and a divider, operating in binary.

Once processing was finished, you naturally needed to convert out of
binary, into what we called 'binny-10' or 'binny-sterling' depending
on the requirement. So a special box was designed for that job.

To allow simultaneous printing and calculation, we included a print
buffer - certain tracks on the drum reserved for storage of
printer data. The drum capacity was increased to 1024 words at this
stage: later, on the successor 1202, it was quadrupled to 4096 words.

We sold, or at least we delivered, 125 1201s and 1202s. That was more than
all the other contemporary British computers put together, so it was a
significant achievement.

To finish on a sad note, the recent death of Harold Ashforth, BTM's
first programmer, means that all of the people involved on both the
500-series Calculators and the HEC computers have now gone except
Lorin Knight and myself.

Editor's note: this is an edited version of a talk given by Dr
Bird to the Punched Card Reunion at Stevenage on 6 October 1998.

Getting Stevenage up to Speed

Mike Forrest

In the run up to development of the 1900 series I had visited RCA at
West Palm Beach to explore RCA's introduction of "The Standard
Interface" on a machine that ICT might sell as a successor to the
very successful 1301/1500. This was the putative 2201.

My strongest memories of that particular spell in the US are of other
aspects of technology than processors, particularly the Bryant Fixed
Disc and the Electra turbo-prop plane.

The Bryant, which stored less data that you can get today on a Zip
disc cartridge but weighed several tons, was hung about with awful
warnings as to what would happen if things went wrong. They frequently
did. We used to leave it running on test overnight in perpetual
anticipation that next morning we would find it had seized up, or
broken loose, or both.

The other technological memory is of flying between Philadelphia and
Miami on Electra turbo-props. The seat rows level with the propellors
tended to be empty, because there had been instances of blades coming
off and spearing passengers in the cabin. There was always room there
to lie across the seats.

This visit to West Palm Beach was in March and April 1963. Later that
year I became acting head of what was eventually called, rather
grandly, Computer Division of Data Processing Equipment Group. It had
a sister division concerned with peripherals, headed by Brian
Maudsley. Brian and I both reported to 'Echo' Organ, who thus became
my seventh boss in as many years (the first, who had recruited me,
left before I arrived, while his successor only survived a few weeks
after I joined).

In the run up to the 1900 development programme, Stevenage had been
involved with a version of the 1300 series fitted with the ICT
Standard Interface for peripherals (it should really be called the
ICT/RCA Standard Interface). This version of the 1301, known as the
1302, as well as being a deliverable product, formed an extremely
valuable testbed for the interface's subsequent application to the
whole 1900 series, where it was a distinguishing hallmark of the
range.

My perception is that the Standard Interface represented an important
step forward in the industry, and can be seen as the precursor of the
more famous OSI seven layer communications standards. Certainly it has
its place in the distinguished line of ideas whose development and
application pioneered the move towards portability, culminating in
Unix and, more by accident than design, the compatible PC.

Whatever its historical significance, the ICT Standard Interface
certainly allowed the development at reasonable cost of a range of
peripherals whose extent was an important strength of the 1900 series.
Indeed, the very number of different peripherals became something of a
burden.

When the order book for the early 1902 and 1903 deliveries started to
build up, it soon became clear that every configuration was different.
The most exotic ones always seemed to be for delivery somewhere
thousands of miles away - Brisbane was a favourite.

Stevenage was allocated the development of the 1902 and 1903, the
small processors in the range. The 1900 series was to be order code
compatible from top to bottom, and the medium of compatibility was the
Executive. It would, I think, be fair to say that this was the time
when software overtook hardware as the real focus of innovation in the
development of computer systems.

It was also the stage when hardware engineers made a personal
transition to the realities of the modern world. Before then, they
invented clever circuits with expensive profligacy. The advent of
software and thus of the programming hordes demonstrated that there
was a much more fertile field for spending money in great quantities
than we hardware electronic engineers had ever found!

As a result, it became imperative that hardware be more standardised,
to avoid the cost of software drowning the forward march of computing.
It is interesting to realise now that at this time the cost of a unit
of hardware capability was not falling year on year, in the way that
happened with the advent of integrated circuits.

I remember proving conclusively that we could not afford to build
circuits in a standard manner because of the redundancy that would be
involved by not using all the inputs on a gate circuit in each of its
instantiations.

One suggestion was that prototypes and early production models would
be built with all gate inputs populated by components: when the design
settled down the redundant diodes and other components on unused gate
inputs would be omitted. Fortunately the prospect of logistics
cock-ups was averted when this misplaced application of ingenuity was
killed by common sense!

But the software people, who always seemed to be paid more, soon
showed that their costs swamped those of the hardware people. So it
became the role of the hardware engineers to make it easier for the
programmers. Sometimes we hardware people wondered why the software
specialists did not try harder to make it easier for themselves.

The other thing that forced hardware standardisation was the need for
increased reliability. Only circuits used many times in a product
could have the exposure during development to ensure this.

A crucial reason why the 1902/1903 activity got off to such a flying
start was the existence of the ex-EMI team (most of whom had worked on
the EMI4 which had just been dropped). They were very skilled at
working together. Indeed, I felt a stranger in my own shop sometimes,
coming as I did from the "old" part of the Stevenage foundation, so
dominant were the ex-EMI engineers. When I later moved to the software
division at Bracknell I again felt a stranger in my own shop, till I
realised that I needed to grow my hair about a foot longer not to be
thought to be a visitor!

Another factor contributing to the speed of ramp-up on 1900 at
Stevenage was the manner of the announcement. As I said earlier, there
were two development divisions at the time - Computers and
Peripherals. About 200 people from those divisions, including the
teams working on the PF182 and PF183 processors, were called into the
canteen at the end of an afternoon and told there and then that ICT
would do the 1900 as a series, that it would have the Standard
Interface, and that Stevenage would do the "conventional"
peripherals and the 1902 and 1903 (and by implication, later the
1901).

Echo Organ took only about five minutes to say this, and then said to
Brian Maudsley, Bill Talbot and me (who were standing beside him) that
it was up to us to get on with it fast.

Even at this early stage, therefore, two key elements were already
rigorously technically defined - the Standard Interface, and the
order code of the processors (by virtue of the prior existence of the
FP1600/1900). In addition, the family of logic circuit cards to be
used already existed in the FP1600. I may be wrong, but I cannot
recollect designing a single further circuit for use in the processor
logic.

In retrospect it is clear that these factors short-circuited the usual
(characteristically British) tendency to argue with everything and to
seek to re-invent everything in their own image. Instead, the task
became at a stroke that of turning rules into an implementation, and
having that running and manufacturable in record time.

I have ever since believed that having plenty of time to do something
is the enemy of getting it done. A similar analysis can be made to
account for the IBM 360 getting done. A "realistic" prior estimate
of a complex project will ensure either that it is never started or
that it overruns catastrophically (because it will be seen in the
early stages to leave time for "optimisation", which often means
conflicting approaches and vacillation).

The kick-off experience also demonstrated to me the validity of
Cardinal Newman's remark that

"Deductions have no power of persuasion
Men will live and die upon a dogma".

Our dogma was that we had 12 months to demonstrate that we could play
our part in a development that it was clear the company was being bet
on.

Nevertheless, for me personally it seems little short of a miracle
that the 1902 and 1903 got done. At the start I did not believe it
would happen. But the team working on it seemed confident, so I came
to believe it too.

There was a crucial stage when we started attaching the peripherals.
This led to fierce battles between the two local divisions, with each
believing, when the products did not work correctly together, that the
other was at fault. The saving grace proved to be that the 1302 was
standing there and working. It became the definition of the Standard
Interface: if a peripheral worked on the 1302, then that peripheral
was by definition "right", and conversely.

Brian Maudsley and I had offices between which was sandwiched a common
secretary's office, into which they both opened. Maybe the real credit
for war not breaking out should go to the occupant of that office,
Daphne Normandale.

Just as the 1302 became the definition of the Standard Interface, so
the 1904/1905 (ie the FP6000) became the definition for the
processors. If a "user level" program executed on that, it was
imperative that it also executed correctly on the 1902/1903. If it
didn't, the 1902/1903 had to be changed so that it did.

The Executive provided the practical medium in which to incorporate
changes to bring this about. It was clear even at the time that the
amount of changes required to the back-wiring (that is, to the
electronically implemented logic) as we went along was a great deal
less than for earlier systems that did not have this developed concept
of an Executive.

These precepts formed the bedrock of the work at Stevenage. Some in
the early stages bemoaned the lack of freedom to try their own ideas
when they conflicted with the precepts. This was understandable: they
had been highly innovative in the past, and part of the early
traditions of the computer industry everywhere was to make as many
different machines as could be conceived.

These frustrations gradually disappeared, but the sheer momentum of
the work became nerve racking. Much of what would now be called the
"intellectual property value" rested in the Executive, which was
kept on paper tape. Paper tape is notorious for its tendency to snarl
up. It was not the most familiar medium at Stevenage either, as the
site had been nurtured on punched cards.

A competition between the hazards and adverse consequences of dropping
a deck of cards and of snagging a reel of paper tape would be a close
run thing. A lot of anguish and not a little righteous anger
surrounded accidents with both. Woe betide a visitor (or manager!) who
intruded into an Executive testing session and, trying to be helpful,
became party to such an accident. Or, even worse, pocketed some paper
tape as a souvenir.

One of the more interesting and fraught areas was magnetic tape. The
transports that ICT was using on the small 1900s came from several
sources. One was American (Potter) and another French. A common
element was that our contacts in both suppliers tended to be oversized
personalities.

I recollect a trip with Arthur Humphreys to Potter's factory in Puerto
Rico via New York, which was Potter's base. The Potter sales director
accompanying Arthur spent most of the flight sitting on the arm of
Arthur's first class seat, making the journey excruciatingly
uncomfortable for both of them.

The French tape deck supplier was, rather confusingly, known as CDC,
which stood in this instance for Compagnie des Compteurs. Even more
confusingly, un compteur is a water or electricity meter, not a
computer. CDC made these as well as tape decks for ordinateurs.

We had problems with some of our home grown peripherals, especially
card readers. There were two varieties of these, the photo-cell
reading electronics of which I had had the misfortune to have designed
personally. But the CDC tape decks excelled everything in their
ability to go haywire.

They had mechanical rather than vacuum tube tape buffers, with all the
opportunity that presented for tape maltreatment. It was no great
challenge to write a sort program that would hit a resonance with
spectacular results. But our contact at CDC, Oscar Cytrin, was charm
personified.

I mention this matter of magnetic tape to emphasise just how large a
proportion of effort and anguish was associated with mechanisms rather
than electronics and software. In retrospect, I am sure that the
peripherals occupied the greater proportion of my time, even though I
was officially only in charge of the processor division. But perhaps
this was because the processor people made sure I was sufficiently
occupied to keep out of their way while they got on with the real
work!

After the peripherals, the core store was the most marginal, and
therefore troublesome, element in the system. There were two
speeds - six microseconds and two microseconds. The faster was the
more reliable, which demonstrated the importance of good engineering
design.

A little light arithmetic shows that every word weighed about 15
grams. In today's memory modules you get about 1000 words for every
gram.

At this distance in time it is not easy to discern the shape of the
day to day activities, but the decision to exhibit at the Business
Efficiency Exhibition at Olympia served a crucial role in pacing the
operation. I suspect that without it, the Stevenage product - both
processors and peripherals - would have reached customers' offices
at least six months later. Such is the power of the absolute deadline.

The decision to exhibit was not as sharp as that which was made to
begin the overall endeavour. There were those who thought it would
divert attention from the development itself. Others feared it would
make the problems of sustaining revenue from older products before
1900 deliveries built up even more difficult. My view on this last
point is that many more businesses sink because they are undermined by
new products from competitors than ever founder because of competition
from their own offerings.

Once the decision was taken, the couple of months before the
exhibition seemed somehow unreal. All I can remember are vignettes of
bizarre hours worked. I do remember moving from my home in
Ashwell - only about 15 miles from Stevenage - into a hotel in
Stevenage itself, so as to be closer at hand in the middle of the
night. I can't remember if I did this because my wife was complaining
at my odd hours: if so she must have given up on that soon afterwards.

I do remember that Stevenage still had a manual public phone exchange
at the time. To make it possible for me to be called in (no pagers or
mobile phones then), one of the hotel's few outside lines was plugged
directly to my bedroom.

During my first night at the hotel, the people working on the machines
felt that my greatest contribution would be to keep away, so they did
not call me out. But I had taken five bookings for the hotel by the
time its staff came on duty next morning!

The prototype 1903 was duly exhibited at Olympia, and the show was
judged a massive success for the 1900 series as a whole. Contrary to
some subsequent stories, what was demonstrated was largely
real - there was little manual twisting of tape reels from behind
by hidden hands.

One story was true, though. Only a few days before the machine was
shipped to the exhibition, the core store of the 1903 was lifted into
the processor frame from the floor where it sat for many previous
months. The frame collapsed under the unaccustomed weight!

Returning to the peripherals, there was an elaborate schedule
specifying which devices should have been tested on the 1902/1903 by
which dates, and we had to report on progress against this schedule
weekly. The information went from Stevenage to the planners (who were
I think based at Kenton), where it was incorporated into a
consolidated report (and then appeared to go to a whole army of
internal critics).

I starkly remember the planners' ability to make it appear that
no deadline was ever quite met. I equally remember, and I hope they do
too because they were meant to, my determination they should recognise that
it was easier to report the work of others than to do it oneself.

Maybe the whole thing was a piece of planned abrasive friction to
motivate everyone. When I later became a planner, the goodies and
baddies of course seemed miraculously to have changed places!

There were genuine difficulties with the peripherals. They contained a
wealth of special circuits to drive solenoids and suchlike. These were
not always so well shaken down by replicated use as the processor
electronics.

They also pushed the contemporary generation of semiconductors very
hard. The printer hammer drivers had to deliver quite a few amps into
the solenoids. And the physical media involved - especially the
older kinds like punched cards - were being moved around at speeds
which in retrospect can be seen to be the end of their evolutionary
performance development. There is nothing quite like a good high speed
card reader jam or spill to teach the rudiments of self-control and
the malevolence of inanimate objects.

Another irritation was that the peripherals were always in the way,
being bulky and well provided with sharp corners.

Naturally the Olympia exhibition was not the end of the task. We had
to establish production as well as build a couple of prototypes. In
many ways that proved the harder task.

The later market history of the 1900 series was impressive. But there
was a sting in the tail for me. I had moved from Stevenage to the
Sales Department, and was selling 1900s to universities and research
organisations, competing against English Electric's System 4.

Later, after another move, this time to Planning, and after the
formation of ICL, I visited a research organisation to which I had
earlier lost the order to a System 4. The customer, having had
problems with the machine, roundly berated me for being such a poor
salesman as to have failed to persuade him to buy a 1900 which, he now
recognised, would have been a much better choice. So his problems were
the System 4 were all my fault too!

The danger of retrospection is that it seldom does justice to
individuals. This article has certainly not done so. But to mention
individual names risks making hurtful and unjust omissions. I must
however mention two who are no longer alive - Ron Feather and Bill
Talbot.

It is often not those who are noisiest at the time who are the most
deserving of credit. It may be that those who most stoically accepted
that what had to be done was essentially a challenging implementation
task rather than an opportunity for innovation made some of the
greatest contributions simply by not rocking the boat.

To those who did this, I would dedicate this thought: "In this
business you can either make things happen, or take the credit for it,
but not both".

Editor's note: this is an edited version of the talk given by the
author to the Society during the ICT/ICL 1900 seminar at the Science
Museum in May 1996.

Obituary: Charlie Portman

One of our industry's most inspiring engineers, ECP Portman (known to
everyone as Charlie) died on 19 December 1998 five weeks after his 65th
birthday and on the threshold of his retirement from ICL.

Charlie graduated in Electronic Engineering from the University of Liverpool
and joined the Ferranti Computer Department in the Magnetic Drum Laboratory
in 1954. He was soon involved with the new Mercury and Sirius computers,
where he first showed his grasp of overall system engineering.

In 1960 he became part of the Orion 1 design team, where his clear
understanding of the interaction of software, hardware and a desired system
specification could be brought to bear on the pioneering work of
multiprogrammming. Charlie took the first (unfinished) Orion to AB Turitz in
Gothenburg and there completed the hardware and software so that it was
accepted by the customer. This was a major manifestation of his skill in
motivating staff of different disciplines to achieve a goal in difficult
circumstances.

As the best system engineer in West Gorton he led all the new 1900 series
hardware development there, and also participated in product planning for
these larger systems. Once the hardware designs were established, he took on
responsibility for all hardware-oriented software for large systems, that is
test software, executive-type software and design automation. He then carried
this work through into the corresponding support for the early large-scale
2900 series machines.

Charlie then turned towards advanced developments, particularly the
exploitation of the falling costs and proliferation of silicon technology,
the architecture of very large systems, and the role of federated and
networked systems, when all these ideas were in their infancy. Charlie was
appointed an ICL Fellow in 1997, and was awarded a Chairman's Medal in 1998.

In the last few years he had taken an active role in the affairs of our
Society, leading the Manchester Pegasus Working Party, and playing a key role
in the SSEM Rebuild team. He had further ambitions for the CCS in his
retirement, which now tragically he has been denied. His very many friends
and colleagues will miss his warmth and wise counsel.

Letters to the Editor

Dear Nicholas,

In his interesting article on the ICT 1301 series Hamish Carmichael comments
on the Powers Samas plans to sell a Ferranti machine named Pluto. This was
indeed a Pegasus and was the elder twin of the machine now at the Science
Museum; both machines had extra character handling instructions and
additional store of 336 bit delay lines, but they preceded Pegasus 2. Pluto
itself was set up at Whyteleafe in Surrey where Powers connected their own
latest card equipment, including interstage punching, and the ambitious
Samastronic printer. Problems with the Samastronic delayed commissioning but
Pluto itself was later delivered to the London and Manchester Assurance
Company.

Hamish also refers to the 'Manchester Autocode' on the 1301, and this was
apprently based on the system written at Manchester University and widely
known as Mercury Autocode\,---\,it was no doubt renamed for the 1301 because
Mercury was then a competitor's machine. Pegasus Autocode was different,
being based on Tony Brooker's earlier system on the Manchester Mark I.

Yours sincerely,

Derek MilledgeBracknell, Berkshire21 March 1999

Dear Mr Enticknap

I read with interest the article on the Ferranti Argus in the last edition of
Resurrection. In 1994 I took a tour of the Hartlepool Nuclear Electric
plant, where the computer room was proudly on display. You may well imagine
my surprise to see Ferranti logos on the equipment, and further enquiry with
the guide alleged the machines to be Argus computers of 22 year vintage. She
was however keen to stress that the machines still delivered the reliability
they required, and that there were no plans for replacement.

Yours faithfully,

Adrian CornforthRochdale27 January 1999

To the Editor,

It was a delightful prod to the memory to read the piece by Stewart Hine. I
was one of the apprentices drafted in by Ron Clayden to work on the pilot
machine in 1954 at the ripe old age of 18. I wonder how many of your readers
of that era are still active in computer circuit design? As Chairman of
Mosaid Technologies in Canada I am still reasonably current on circuit issues
as they relate to 256M memory chips. A far cry from the drum I too remember!

I too can claim that the experience stood me in good stead. The "Margin
Test" technique was the inspiration for the first paper I gave on a memory
chip (at the 1975 ISSCC conference, on a marginally testable 4K DRAM). Many
other links from all those years ago to more recent stuff can be found over
the 45 years.

I think I can add to the 6F33 story. As a new division, we were chronically
short of the most basic needs. Management was not amused when, on a senior
level visit, we drew with chalk "Fire" (we were cold) and "cupboard" with
a few bits scattered. Then an engineer was transferred to us from the Radio
Altimeter group. He came with a cupboard. It was full of components,
including boxes of 6F33s. The cupboard was coveted more than the parts,
though I guess now that some 6F33s might have been retained. The suggestion
was made to send them back to the Ministry, but it was immediately rejected
on the grounds that they would then ask where the rest were!

The solution was to pile it all up on the floor and let it be known this was
stuff no longer wanted. The apprentice locusts duly cleared up fast. Most of
us (all I guess) were avid hobbyists.

The best legacy I received from my days at EMI was the best management
training I could wish for. Avoiding the incredibly stupid practices observed
daily and their catastrophic consequences for the company has been a beacon
ever since. I subsequently made the effort to combine management studies
(then part of Mechanical Engineering) at Newcastle while having the great
good fortune to be tutored by one of the WWII greats in radar, FJU Ritson, an
FC Williams co-worker (FCW was my PhD external examiner). All that happened
after that is another story.

Society Activity

Preservation Policy Working GroupSimon Lavington

The Society is compiling an index of hardware, software and documentation
from UK-designed computers of the period 1948-1970. A checklist of these
machines is given below, from which it will be seen that analogue and
non-stored program computers are excluded. The date shown is the approximate
year of first operation or delivery.

Although very few pre-1970 computers still exist, it is believed that
individuals and organisations have kept bits of hardware, manuals, program
listings, peripherals and so on, which have now become of considerable
historical interest.

The purpose of the CCS index is therefore to document the technical details
and present location of all pre-1970 artefacts which could (by prior
arrangement) be studied by bona fide researchers. A summary of the
index will be made available electronically, though sensitive information
such as private addresses would naturally not be publicised.

Individuals or organisations holding early computer artefacts are invited to
contact me, by e-mail at <lavis at essex dot ac dot uk> or by phone or mail (see
inside back cover.

Checklist of pre-1970 UK-designed computers

Machine

Year

Ace (NPL)

1957

AEI 1010

1960

APE(X)C (Birkbeck)

1952

ARC (Birkbeck)

1949

BTM 1200 series

1954

BTM HEC

1953

Cadet (Harwell)

1955

Computer Technology Modular One

1968

Edsac (Cambridge)

1949

Edsac II (Cambridge)

1957

Digico Digiac

1966

Digico Micro 16

1968

Elliott 152, 153

1950?

Elliott 401

1953

Elliott 402

1955

Elliott 403

1957?

Elliott 405

1956?

Elliott 502

1961?

Elliott 503

1962?

Elliott 802

1958

Elliott 803

1959

Elliott 4100 series

1966

Elliott 900 series

1966?

Elliott Nicholas

1952

EMI EBM

1957

Emidec 1100

1959

Emidec 2400

1961

English Electric Deuce series

1955

English Electric KDF6

1963

English Electric KDF7

1965?

English Electric KDF8

1962?

English Electric KDF9

1963

English Electric KDN2

1962

English Electric KDP10

1961?

(English Electric System 4 (RCA Spectra)

1968?)

Ferranti Apollo

1961

Ferranti Argus series

1963?

Ferranti Atlas

1962

Ferranti Hermes

????

Ferranti Mark 1

1951

Ferranti Mark 1*

1953

Ferranti Mercury

1957

Ferranti Newt

1959

Ferranti Orion

1963

Ferranti Pegasus

1956

Ferranti Perseus

1959

Ferranti Poseidon

1962?

Ferranti Sirius

1961

GEC 90xx series

1964

GEC S7

1966

ICT 558 FCC

1962

ICT 1300 series

1961

(ICT 1500 (RCA 301)

1963?)

(ICT 1600 (RCA 3301)

1965?)

ICT 1900 series

1965

Leo

1951

Leo II

1957

Leo III

1962

Manchester experimental transistor computer

1953

Manchester Mark I

1949

Manchester Meg

1954

Manchester SSEM

1948

Marconi Arch 1000

1963

Marconi TAC

1961

Marconi Myriad

1963

Metrovic MV950

1956

Mosaic (MoS)

1953

Pilot Ace (NPL)

1950

RREAC (RRE)

1961?

Smiths Seca

1955?

SEC (Birkbeck)

1950?

Stantec Zebra

1958

Titan (Cambridge)

1963?

Treac (TRE)

1953

Recording of Personal HistoriesSimon Lavington

Many Society members and others have from time to time expressed a wish to
help in recording the history of British computing. Hitherto it has been
difficult to capitalise on this willingness. The Society is now interested in
collecting the personal reminiscences of anyone who was involved in the
design, production or use of pre-1970 UK computers, especially during the
pre-1960 period. If you have anecdotes, please consider writing them down or
making an audio cassette. The material will be placed in the CCS archives for
consultation by researchers. Again please contact me for further information.

Elliott 401 Working PartyChris Burton

A little progress has been made with the power system, such as that the
cooling fans have been brought up to speed. A small step, but it gives us
confidence that the precautions we are taking with the old wiring insulation
are worthwhile.

Bombe Rebuild ProjectJohn Harper

Our redrawing exercise is not quite complete but this no longer holds back
the drawing activity in any way. We can now proceed as quickly as effort,
resources and funds allow, with confidence, knowing that the remaining
drawings have no impact on the parts we are currently manufacturing. The
final drawing phase, which is mostly electrical, can now be completed in
parallel with mechanical construction.

Progress on the physical aspects of the rebuild are proceeding slowly but
surely, but again not all of this is visible at Bletchley Park. What can be
seen, at the time of writing in early July, is that all four horizontal bars
are complete and in place and the majority of front and rear plates are test
fitted to these bars.

To the casual observer this may not look much, but to those involved this is
a great relief because we have proved that nearly 1000 holes hand drilled
and many of them tapped out with threads to take the fixing screws are all in
the correct places. We have also proved that the front and rear plates made
using Computer Aided Design techniques from our new drawings are correct. The
fact that this whole assembly measuring around six feet by five feet fits
squarely into our previously manufactured frame is a great consolation to
those who have put in so much effort.

Not visible at Bletchley Park is the construction of other units. The hinged
gate which carries the jacks into which the menu is plugged is nearing
completion and should be fitted around early September. There are many other
items on the go but the most impressive is the main gearbox casting which has
now been successfully cast in high grade iron from modern patterns made from
3D files which a member of our team produced. Modern patterns were produced
using the resources of the Rapid Prototyping Centre described in my last
report in Resurrection issue 21. The casting is most impressive and
weighs 41 lbs. We now need to find somebody to machine it!

Those interested in reading more about our project may visit our Web site at
<www.jharper.demon.co.uk/bombel.htm>.

The project still needs a great deal of help and support as described in
previous reports with the most immediate being to locate people with turning
facilities. If you are able to help with this or any of the other activities
mentioned in earlier reports please contact me by e-mail at
<bombe at jharper dot demon dot co dot uk> or by phone or mail (see inside back cover).

Pegasus Working PartyLen Hewitt

Tha machine has worked well over the past few months. We have intermittent
and permanent faults, but none very serious. We are still very short of spare
42- and 35-bit lines. If anybody out there has any T for torsional type lines
around as souvenirs we would be prepared to swap a longer 360-bit line for a
42- or 35-bit 6T line.

The good news is that Pegasus is to move into the Computing Gallery at the
Science Museum, possibly this summer, and will be set up as a working
exhibit, with its working periods to be determined by the museum.

Pegasus has been running for several hours on a fortnightly basis at Blythe
Road. Unfortunately it has not been posssible to have the "In steam" days
as we had in the old Science Museum canteen, but it is hoped to arrange
something similar when the move has taken place and the machine is working
again.

Simulators

Simulators for a variety of historic computers, including Edsac,
Elliott 903, Pegasus, the Manchester University Small-Scale Experimental
Machine and Zebra, can be found at our FTP site. Access details are on page
36.

Forthcoming Events

21-22 August 1999, and fortnightly thereafter Guided tours and
exhibition at Bletchley Park, price £3.00, or £2.00 for
concessionsExhibition of wartime code-breaking equipment and procedures,
including the replica Colossus, plus 90 minute tours of the
wartime buildings

21 September 1999 North West Group meeting on "The Doomsday Project"
Speaker Professor Stephen Heppel

The North West Group meetings will take place in the Conference room at the
Manchester Museum of Science and Industry, starting at 1730; tea is served
from 1700. The London meetings on 13 October and 16 December will take place
in the Director's Suite at the Science Museum, and the talk on 18 November in
the Museum's Lecture Theatre.

Queries about London meetings should be addressed to George Davis on
0181 681 7784, and about Manchester meetings to William Gunn on 01663
764997.

FTP, Web and E-mail Addresses

The Society has its own World Wide Web (WWW) site: it is located at
http://www.cs.man.ac.uk/CCS/. This is in addition to the FTP site at
ftp.cs.man.ac.uk/pub/CCS-Archive.
Our Web site includes information about
the SSEM project as well as selected papers from Resurrection.
Readers can download files, including the current and all past issues of
Resurrection and simulators for historic machines.

Readers of Resurrection who wish to contact committee members
via electronic mail may do so using the following addresses.

[The printed version contains the email addresses of Committee members]

Aims and objectives

The Computer Conservation Society (CCS) is a co-operative venture
between the British Computer Society, the Science Museum of London
and the Museum of Science and Industry in Manchester.

The CCS was constituted in September 1989 as a Specialist Group of
the British Computer Society (BCS). It thus is covered by the Royal
Charter and charitable status of the BCS.

The aims of the CCS are to

Promote the conservation of historic computers and to identify existing
computers which may need to be archived in the future

Develop awareness of the importance of historic computers

Encourage research on historic computers and their impact on society

Membership is open to anyone interested in computer conservation and
the history of computing.

The CCS is funded and supported by a grant from the BCS, fees from
corporate membership, donations, and by the free use of Science Museum
facilities. Membership is free but some charges may be made for
publications and attendance at seminars and conferences.

There are a number of active Working Parties on specific computer
restorations and early computer technologies and software. Younger people
are especially encouraged to take part in order to achieve skills transfer.

The corporate members who are supporting the Society are ICL and Vaughan Systems.

Resurrection is the bulletin of the Computer
Conservation Society and is distributed free to members. Additional
copies are £3.00 each, or £10.00 for an annual
subscription covering four issues.